WO2018066858A1 - Procédé et appareil pour supporter une multidiffusion de nb-iot dans un système de communication sans fil - Google Patents

Procédé et appareil pour supporter une multidiffusion de nb-iot dans un système de communication sans fil Download PDF

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WO2018066858A1
WO2018066858A1 PCT/KR2017/010573 KR2017010573W WO2018066858A1 WO 2018066858 A1 WO2018066858 A1 WO 2018066858A1 KR 2017010573 W KR2017010573 W KR 2017010573W WO 2018066858 A1 WO2018066858 A1 WO 2018066858A1
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cell
ptm
mbms
ranking
frequency
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PCT/KR2017/010573
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English (en)
Korean (ko)
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이영대
구관모
김상원
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엘지전자 주식회사
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/24—Reselection being triggered by specific parameters
    • H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
    • H04W36/302—Reselection being triggered by specific parameters by measured or perceived connection quality data due to low signal strength
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06—Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Definitions

  • the present invention relates to wireless communication, and more particularly, to a method and apparatus for supporting multicast of narrowband internet-of-things (NB-IoT) in a wireless communication system.
  • NB-IoT narrowband internet-of-things
  • 3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communication. Many approaches have been proposed to reduce the cost, improve service quality, expand coverage, and increase system capacity for LTE targets. 3GPP LTE is a high level requirement that requires cost per bit, improved service usability, flexible use of frequency bands, simple structure, open interface and proper power consumption of terminals.
  • LTE category 0 a low complexity terminal developed based on existing LTE technology in LTE Rel-12, has been defined.
  • LTE category M1 supporting a narrow band of 1.4 MHz is defined in LTE Rel-13.
  • a new radio access technology (RAT) technology, NB-IoT (narrowband IoT), which is based on a 200KHz bandwidth that can be operated independently without requiring backward compatibility has also been defined in LTE Rel-13.
  • RAT radio access technology
  • NB-IoT narrowband IoT
  • Low-power, low-cost optimized wireless technologies such as LTE category M1 and NB-IoT require requirements that are in contrast to LTE technologies that previously required high throughput and high mobility.
  • Mobility management in LTE includes cell reselection performed in the idle state of the terminal.
  • the UE In the idle state, the UE camps on one cell and may continuously perform cell reselection according to cell reselection criteria to find a good cell.
  • the terminal may perform cell reselection using frequency priority information. That is, the terminal may measure the frequency based on the frequency priority information, and may determine which frequency is considered first when performing cell reselection. If a good cell is found, this cell is selected.
  • a method for improving a cell reselection procedure of an NB-IoT terminal may be required.
  • the present invention provides a method and apparatus for supporting multicast of narrowband internet-of-things (NB-IoT) in a wireless communication system.
  • the present invention provides a method for improving a cell reselection procedure to support multicast of NB-IoT.
  • the present invention provides a method of performing cell reselection by increasing the ranking of a cell providing multimedia broadcast multicast services (MBMS) through an offset through single-cell point-to-multipoint (SC-PTM).
  • MBMS multimedia broadcast multicast services
  • SC-PTM single-cell point-to-multipoint
  • a method of performing cell reselection by a user equipment (UE) in a wireless communication system determines that it is interested in receiving multimedia broadcast multicast services (MBMS), and determines a value based on a measurement result of a single-cell point-to-multipoint (SC-PTM) cell providing the MBMS. Adding a SC-PTM offset to determine the ranking of the SC-PTM cell, and performing ranking based cell reselection according to the determined SC-PTM cell ranking.
  • MBMS multimedia broadcast multicast services
  • SC-PTM single-cell point-to-multipoint
  • the UE may be either a narrowband internet-of-things (NB-IoT) UE or a UE in enhanced coverage.
  • NB-IoT narrowband internet-of-things
  • the UE may be a UE capable of receiving the MBMS via SC-PTM.
  • the MBMS can be received only while the UE camps on the frequency at which the MBMS is provided.
  • the SC-PTM offset may be applied to all cells on all frequencies providing the MBMS.
  • the method may further include receiving a system information block type 20 (SIB20) including a list of the SC-PTM cells from a serving cell.
  • SIB20 system information block type 20
  • a user equipment (UE) in a wireless communication system includes a memory, a transceiver, and a processor connected to the memory and the transceiver, wherein the processor determines that it is interested in receiving multimedia broadcast multicast services (MBMS) and provides the MBMS To determine the ranking of the SC-PTM cell by adding an SC-PTM offset to a value based on the measurement result of a single-cell point-to-multipoint (SC-PTM) cell, and to the ranking of the determined SC-PTM cell According to the ranking based cell reselection is performed.
  • MBMS multimedia broadcast multicast services
  • the probability of reselection of a cell providing an MBMS through the SC-PTM may be increased.
  • 1 shows a structure of a 3GPP LTE system.
  • FIG. 2 is a block diagram of a user plane protocol stack of an LTE system.
  • FIG. 3 is a block diagram of a control plane protocol stack of an LTE system.
  • FIG. 5 illustrates a method of performing cell reselection according to an embodiment of the present invention.
  • FIG. 6 illustrates a method of performing cell reselection according to another embodiment of the present invention.
  • FIG. 7 illustrates a wireless communication system in which an embodiment of the present invention is implemented.
  • a 3GPP long-term evolution (LTE) system structure includes one or more user equipment (UE) 10, an evolved-UMTS terrestrial radio access network (E-UTRAN), and an evolved packet core (EPC). Include.
  • the UE 10 is a communication device moved by a user.
  • the UE 10 may be fixed or mobile and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device.
  • the E-UTRAN includes one or more evolved NodeBs (eNBs) 20, and a plurality of UEs may exist in one cell.
  • the eNB 20 provides an end point of a control plane and a user plane to the UE 10.
  • the eNB 20 generally refers to a fixed station that communicates with the UE 10 and may be referred to in other terms, such as a base station (BS), an access point, and the like.
  • BS base station
  • One eNB 20 may be arranged per cell.
  • downlink means communication from the eNB 20 to the UE 10.
  • Uplink means communication from the UE 10 to the eNB 20.
  • Sidelink means communication between the UE (10).
  • the transmitter may be part of the eNB 20 and the receiver may be part of the UE 10.
  • the transmitter may be part of the UE 10 and the receiver may be part of the eNB 20.
  • the transmitter and the receiver may be part of the UE 10.
  • the EPC includes a mobility management entity (MME) and a serving gateway (S-GW).
  • MME mobility management entity
  • S-GW serving gateway
  • the MME / S-GW 30 is located at the end of the network.
  • the MME / S-GW 30 provides an end point of session and mobility management functionality for the UE 10.
  • the MME / S-GW 30 is simply expressed as a "gateway", which may include both the MME and the S-GW.
  • a packet dana network (PDN) gateway (P-GW) may be connected to an external network.
  • PDN packet dana network gateway
  • the MME includes non-access stratum (NAS) signaling to the eNB 20, NAS signaling security, access stratum (AS) security control, inter CN (node network) signaling for mobility between 3GPP access networks, idle mode terminal reachability ( Control and execution of paging retransmission), tracking area list management (for UEs in idle mode and activation mode), P-GW and S-GW selection, MME selection for handover with MME change, 2G or 3G 3GPP access Bearer management features, including roaming, authentication, and dedicated bearer setup, selection of a serving GPRS support node (SGSN) for handover to the network, public warning system (ETWS) and earthquake and tsunami warning system (CMAS) It provides various functions such as message transmission support.
  • NAS non-access stratum
  • AS access stratum
  • inter CN node network
  • IMS node network
  • MME selection for handover with MME change 2G or 3G 3GPP access Bearer management features, including roaming, authentication, and dedicated bearer setup, selection
  • S-GW hosts can be based on per-user packet filtering (eg, through deep packet inspection), legal blocking, terminal IP (Internet protocol) address assignment, transport level packing marking in DL, UL / DL service level charging, gating and It provides various functions of class enforcement, DL class enforcement based on APN-AMBR (access point name aggregate maximum bit rate).
  • per-user packet filtering eg, through deep packet inspection
  • legal blocking e.g, terminal IP (Internet protocol) address assignment
  • transport level packing marking in DL e.g, UL / DL service level charging
  • gating Internet protocol
  • An interface for user traffic transmission or control traffic transmission may be used.
  • the UE 10 and the eNB 20 are connected by a Uu interface.
  • the UEs 10 are connected by a PC5 interface.
  • the eNBs 20 are connected by an X2 interface.
  • the neighboring eNB 20 may have a mesh network structure by the X2 interface.
  • the eNB 20 and the gateway 30 are connected through an S1 interface.
  • FIG. 2 is a block diagram of a user plane protocol stack of an LTE system.
  • 3 is a block diagram of a control plane protocol stack of an LTE system.
  • the layer of the air interface protocol between the UE and the E-UTRAN is based on the lower three layers of the open system interconnection (OSI) model, which is well known in communication systems. Hierarchical).
  • OSI open system interconnection
  • the physical layer belongs to L1.
  • the physical layer provides an information transmission service to a higher layer through a physical channel.
  • the physical layer is connected to a higher layer of a media access control (MAC) layer through a transport channel.
  • Physical channels are mapped to transport channels.
  • Data is transmitted between the MAC layer and the physical layer through a transport channel.
  • Data is transmitted over a physical channel between different physical layers, that is, between a physical layer of a transmitter and a physical layer of a receiver.
  • the MAC layer, radio link control (RLC) layer, and packet data convergence protocol (PDCP) layer belong to L2.
  • the MAC layer provides a service to an RLC layer, which is a higher layer, through a logical channel.
  • the MAC layer provides data transfer services on logical channels.
  • the RLC layer supports reliable data transmission. Meanwhile, the function of the RLC layer may be implemented as a functional block inside the MAC layer, in which case the RLC layer may not exist.
  • the PDCP layer introduces an IP packet, such as IPv4 or IPv6, over a relatively low bandwidth air interface to provide header compression that reduces unnecessary control information so that the transmitted data is transmitted efficiently.
  • the radio resource control (RRC) layer belongs to L3.
  • the RRC layer at the bottom of L3 is defined only in the control plane.
  • the RRC layer is responsible for the control of logical channels, transport channels, and physical channels in connection with configuration, re-configuration, and release of radio bearers (RBs).
  • RB means a service provided by L2 for data transmission between the UE and the E-UTRAN.
  • the RLC and MAC layers may perform functions such as scheduling, ARQ, and hybrid automatic repeat request (HARQ).
  • the PDCP layer may perform user plane functions such as header compression, integrity protection and encryption.
  • the RLC / MAC layer (end at eNB at network side) may perform the same functions for the control plane.
  • the RRC layer (terminated at the eNB at the network side) may perform functions such as broadcast, paging, RRC connection management, RB control, mobility functionality, and UE measurement reporting and control.
  • the NAS control protocol (terminated at the gateway's MME at the network side) may perform functions such as SAE bearer management, authentication, LTE_IDLE mobility management, paging start in LTE_IDLE, and security control for signaling between the gateway and the UE.
  • the physical channel transmits signaling and data between the physical layer of the UE and the physical layer of the eNB through radio resources.
  • the physical channel is composed of a plurality of subframes in the time domain and a plurality of subcarriers in the frequency domain.
  • One subframe of 1ms consists of a plurality of symbols in the time domain.
  • a specific symbol of the corresponding subframe, for example, the first symbol of the subframe may be used for the PDCCH.
  • the PDCCH may carry dynamically allocated resources, such as a physical resource block (PRB) and modulation and coding schemes (MCS).
  • PRB physical resource block
  • MCS modulation and coding schemes
  • the DL transport channel is a broadcast channel (BCH) used for transmitting system information, a paging channel (PCH) used for paging a UE, and a downlink shared channel (DL-SCH) used for transmitting user traffic or control signals.
  • BCH broadcast channel
  • PCH paging channel
  • DL-SCH downlink shared channel
  • MCH Multicast channel
  • the DL-SCH supports dynamic link adaptation and dynamic / semi-static resource allocation by varying HARQ, modulation, coding and transmit power.
  • the DL-SCH may enable the use of broadcast and beamforming throughout the cell.
  • the UL transport channel generally includes a random access channel (RACH) used for initial access to a cell, an uplink shared channel (UL-SCH) used for transmitting user traffic or control signals.
  • RACH random access channel
  • UL-SCH uplink shared channel
  • the UL-SCH supports dynamic link adaptation with HARQ and transmit power and potential changes in modulation and coding.
  • the UL-SCH may enable the use of beamforming.
  • Logical channels are classified into control channels for information transmission in the control plane and traffic channels for information transmission in the user plane according to the type of information to be transmitted. That is, a set of logical channel types is defined for different data transfer services provided by the MAC layer.
  • the control channel is used only for conveying information in the control plane.
  • the control channel provided by the MAC layer includes a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), and a dedicated control channel (DCCH).
  • BCCH is a DL channel for broadcasting system control information.
  • PCCH is a DL channel for the transmission of paging information, and is used when the network does not know the location of the cell unit of the UE.
  • CCCH is used by the UE when it does not have an RRC connection with the network.
  • the MCCH is a one-to-many DL channel used for transmitting multimedia broadcast multicast services (MBMS) control information from the network to the UE.
  • DCCH is a one-to-one bidirectional channel used by a UE having an RRC connection for transmission of dedicated control information between the UE and the network.
  • the traffic channel is used only for conveying information in the user plane.
  • the traffic channel provided by the MAC layer includes a dedicated traffic channel (DTCH) and a multicast traffic channel (MTCH).
  • DTCH is used for transmission of user information of one UE on a one-to-one channel and may exist in both UL and DL.
  • MTCH is a one-to-many DL channel for transmitting traffic data from the network to the UE.
  • the UL connection between the logical channel and the transport channel includes a DCCH that can be mapped to the UL-SCH, a DTCH that can be mapped to the UL-SCH, and a CCCH that can be mapped to the UL-SCH.
  • the DL connection between logical channel and transport channel is BCCH which can be mapped to BCH or DL-SCH, PCCH which can be mapped to PCH, DCCH which can be mapped to DL-SCH, DTCH which can be mapped to DL-SCH, MCH MCCH that can be mapped to and MTCH that can be mapped to MCH.
  • the RRC state indicates whether the RRC layer of the UE is logically connected with the RRC layer of the E-UTRAN.
  • the RRC state may be divided into two types, such as an RRC connected state (RRC_CONNECTED) and an RRC idle state (RRC_IDLE).
  • RRC_CONNECTED an RRC connected state
  • RRC_IDLE while the UE designates a discontinuous reception (DRX) set by the NAS, the UE may receive a broadcast of system information and paging information.
  • the UE may be assigned an ID for uniquely designating the UE in the tracking area, and perform public land mobile network (PLMN) selection and cell reselection.
  • PLMN public land mobile network
  • no RRC context is stored at the eNB.
  • the UE In RRC_CONNECTED, it is possible for the UE to have an E-UTRAN RRC connection and context in the E-UTRAN to send data to the eNB and / or receive data from the eNB. In addition, the UE may report channel quality information and feedback information to the eNB. In RRC_CONNECTED, the E-UTRAN may know the cell to which the UE belongs. Therefore, the network may transmit data to and / or receive data from the UE, and the network may inter-RAT with a GSM EDGE radio access network (GERAN) through the UE's mobility (handover and network assisted cell change (NACC). radio access technology (cell change indication), and the network may perform cell measurement for a neighboring cell.
  • GSM EDGE radio access network GERAN
  • NACC network assisted cell change
  • radio access technology cell change indication
  • the UE specifies a paging DRX cycle. Specifically, the UE monitors the paging signal at a specific paging occasion for every UE specific paging DRX cycle. Paging opportunity is the time period during which the paging signal is transmitted. The UE has its own paging opportunity. The paging message is transmitted on all cells belonging to the same tracking area (TA). When a UE moves from one TA to another TA, the UE may send a tracking area update (TAU) message to the network to update its location.
  • TAU tracking area update
  • Multicast-broadcast single-frequency network (MBSFN) synchronization area A network area in which all eNBs can synchronize and perform MBSFN transmission.
  • the MBSFN synchronization area may support one or more MBSFN areas. In a given frequency layer, an eNB may belong to only one MBSFN synchronization area.
  • the MBSFN synchronization area is independent of the definition of the MBMS service area.
  • MBSFN transmission or transmission in MBSFN mode Simultaneous transmission transmission technology implemented by transmitting the same waveform from multiple cells simultaneously. MBSFN transmissions from multiple cells in the MBSFN area are seen as a single transmission by the UE.
  • the MBSFN area consists of a group of cells within the MBSFN synchronization area of the network and is adjusted to achieve MBSFN transmission. Except for MBSFN area reserved cells, all cells within the MBSFN area contribute to MBSFN transmission and announce availability. The UE may only need to consider if it knows a subset of the configured MBSFN areas, ie which MBSFN areas apply to the service (s) it wishes to receive.
  • MBSFN region reserved cell A cell belonging to the MBSFN region and not contributing to the MBSFN transmission. This cell may be allowed to transmit for other services with limited power in the resources allocated for MBSFN transmission.
  • Each SYNC protocol data unit includes a time stamp indicating the start time of the synchronization sequence.
  • each synchronization sequence has the same duration as configured in a broadcast multicast service center (BM-SC) and a multi-cell / multicast coordination entity (MCE).
  • BM-SC broadcast multicast service center
  • MCE multi-cell / multicast coordination entity
  • the Synchronization Period provides a time reference to the start time indication of each synchronization sequence.
  • the time stamp provided for each SYNC PDU is a relative value representing the start time of the synchronization period.
  • the synchronization period is configurable.
  • the transmission of MBMS in E-UTRAN uses MBSFN transmission or single-cell point-to-multipoint (SC-PTM) transmission.
  • the MCE determines whether to use SC-PTM or MBSFN for each MBMS session.
  • SC-PTM transmission Single cell transmission (ie SC-PTM transmission) of MBMS has the following characteristics:
  • MBMS is transmitted with coverage of a single cell
  • SC-MCCH single-cell MCCH
  • SC-MTCH SC-MTCH
  • SC-MCCH and SC-MTCH transmission are indicated by logical channel specific radio network temporary identity (RNTI) on the PDCCH, respectively (G-RNTI (group RNTI) used for reception of DL-SCH to which SC-MTCH is mapped).
  • RNTI logical channel specific radio network temporary identity
  • G-RNTI group RNTI
  • TMGI temporary mobile group identity
  • a single transmission is used for the DL-SCH to which the SC-MCCH or SC-MTCH is mapped (ie, neither blind HARQ repetition nor RLC fast repetition).
  • Multi-cell transmission of MBMS (ie MBSFN transmission) has the following characteristics:
  • the scheduling of each MCH is performed by the MCE;
  • a single transmission is used for the MCH (ie neither blind HARQ repetition or RLC fast repetition);
  • a single TB (transport block) per TTI is used for MCH transmission, and the TB uses all MBSFN resources in that subframe;
  • MTCH and MCCH can be multiplexed on the same MCH and mapped onto the MCH for PTM transmission;
  • the MAC subheader indicates the logical channel identity (LCID) for the MTCH and MCCH;
  • MBSFN synchronization area, MBSFN area and MBSFN cell are semi-statically configured, for example by operation and maintenance (O &M);
  • the MBSFN area is static unless it is changed by O & M (ie the area is not changed dynamically).
  • MBSFN region includes one or more MCH.
  • the MCH specific MCS is used in all subframes of the MCH, and the MCS indicated in the BCCH is not used. All MCH have the same coverage area.
  • the cell reselection evaluation process will be described. This may be referred to Section 5.2.4 of 3GPP TS 36.304 V13.2.0 (2016-06).
  • the absolute priority of different E-UTRAN frequencies or inter-RAT frequencies may be provided to the UE by inheriting from system information, RRCConnectionRelease message, or other RAT in inter-RAT cell (re) selection.
  • the E-UTRAN frequency or inter-RAT frequency may be listed without providing a priority (that is, there is no cellReselectionPriority field for that frequency). If priority is provided for dedicated signaling, the UE ignores any priority provided in the system information.
  • the UE applies only the priority provided by the system information from the current cell, and the UE is not specified differently. Preserves the priority provided by dedicated signaling and depriortisztionReq received at RRCConnectionReject unless otherwise specified .
  • the UE When the UE is in a camped normally state, if the UE only has a dedicated priority other than the current frequency, then the UE makes the current frequency lower than the lowest priority frequency (ie, any value configured in the network). ) If a UE is camped on a suitable closed subscriber group (CSG) cell and that cell can be connected in normal coverage, the UE will always take the current frequency with the highest priority, regardless of any priority value assigned to this frequency.
  • CSG closed subscriber group
  • a UE capable of sidelink communication is configured to perform sidelink communication and can only perform sidelink communication while camping on a frequency
  • the UE may consider that frequency as the highest priority. have.
  • a UE capable of sidelink discovery is configured to perform public safety related sidelink discovery and can only perform public safety related sidelink discovery while camping on a frequency
  • the UE assigns that frequency to the highest priority. Can be regarded as.
  • the UE may receive MBMS service continuity or SC-PTM reception, is interested in receiving or is interested in receiving MBMS service, and receives the MBMS service only while the UE camps on the frequency where the MBMS service is provided. If possible, the UE may consider the frequency as the highest priority during the MBMS session as long as the following two conditions are met.
  • the UE may have MBMS service continuity and the reselected cell broadcasts SIB13, or the UE is capable of SC-PTM reception and the reselected cell broadcasts SIB20;
  • the SIB15 of the serving cell indicates one or more MBMS service area IDs (SAIs) contained in the MBMS user service description (MBMS USD) for that frequency, or SIB15 is not broadcasted in the serving cell and the corresponding frequency is transmitted to this MBMS service; If included in USD
  • SAIs MBMS service area IDs
  • the MBMS frequency is a DL dedicated frequency that is not camp-on and the UE will only receive MBMS service when camping on a subset of cell reselection candidate frequencies. There may be cases.
  • the UE may consider that frequency as the highest priority during the MBMS session as long as the reselected cell broadcasts SIB13.
  • Unable cell reselection candidate frequencies may be regarded as the lowest priority.
  • Narrowband internet-of-things allow access to network services via E-UTRA, where the channel bandwidth is limited to 180 kHz.
  • the NB-IoT UE is a UE using NB-IoT.
  • NB-IoT provides access to network services using a physical layer optimized for very low power consumption (for example, the total carrier bandwidth is 180 kHz and the subcarrier spacing can be 3.75 kHz or 15 kHz).
  • Multiple E-UTRA protocol functions supported by all LTE Rel-8 UEs are not used for NB-IoT and need not be supported by eNBs and UEs using only NB-IoT.
  • cell reselection identifies the cell that the UE should camp on.
  • Cell reselection may be performed based on cell reselection criteria including measurement of serving cell and neighbor cell as follows.
  • In-frequency reselection may be performed based on cell ranking (potentially with cell specific offset).
  • Reselection between frequencies may be performed based on frequency ranking (potentially having a frequency specific offset).
  • the measurement rule for cell reselection of NB-IoT is as follows.
  • the UE uses the parameters provided by the serving cell.
  • the UE uses the following rules to limit the necessary measurements.
  • the UE may not perform intra-frequency measurements.
  • the UE performs the inter-frequency measurement.
  • the UE applies the following rules for the NB-IoT frequency indicated in the system information.
  • the UE may not perform the inter-frequency measurement.
  • the UE performs the inter-frequency measurement.
  • Cell reselection criteria within frequencies and between frequencies having the same priority are as follows.
  • the cell ranking criterion R s for the serving cell and the cell ranking criterion R n for the neighboring cell are defined by Equation 1.
  • R s Q meas, s + Q Hyst -Qoffset temp
  • Rn Q measn, n -Qoffset-Qoffset temp
  • Q meas, s is a reference signal received power (RSRP) measurement amount of the serving cell used in cell reselection.
  • Q meas, n is the RSRP measurement of neighbor cells used in cell reselection.
  • Q Hyst is a hysteresis value for the ranking criteria.
  • Qoffset is the Qoffset s, n is valid if Qoffset s, n + Qoffset frequency. Otherwise, for NB-IoT, Qoffset is the Qoffset frequency .
  • Qoffset s, n is the offset between two cells.
  • Qoffset frequency is a frequency specific offset for E-UTRAN frequencies of the same priority.
  • Qoffset temp is an additional offset that can be used for cell reselection and is temporarily applied when the RRC connection establishment fails on the cell.
  • the UE determines the ranking of all cells that meet the cell selection criteria S. However, all CSG cells which are known to the UE not as CSG member cells may be excluded. The cell derives Q meas, n and Q meas, s and calculates the R value using the average RSRP result, so that the ranking is determined according to the above R criteria. If the ranking of the cell is ranked as the best cell, the UE performs cell reselection to that cell. In all cases, the UE reselects the new cell only if the following conditions are met:
  • the new cell is ranked higher than the serving cell during the time interval Treselection RAT ;
  • At least 1 second has elapsed since the UE camped on the current serving cell
  • the NB-IoT supports only ranking based cell reselection without consideration of frequency priority.
  • the UE may receive the MBMS during the MBMS session. Can be regarded as the highest priority of the frequencies provided.
  • the NB-IoT UE in idle mode performs only ranking based cell reselection, it may not be able to move to the frequency at which the MBMS is provided.
  • the present invention supports multicast DL transmission.
  • a cell reselection procedure is provided.
  • the UE may be either an NB-IoT UE or a UE in enhanced coverage. That is, the present invention can be applied for multicast support of UEs in enhanced coverage as well as NB-IoT UEs.
  • the present invention proposes three options as follows.
  • Option 1 If the UE is interested in receiving MBMS, the UE may add an offset to the SC-PTM cell when performing ranking based cell reselection. That is, in order to increase the reselection probability of the SC-PTM cell providing the MBMS that the UE is interested in receiving, the UE adds an offset to the ranking of the SC-PTM cell to increase the ranking of the SC-PTM cell and rank based Cell reselection may be performed.
  • Option 2 If the UE is interested in receiving MBMS, the UE may perform ranking based cell reselection only for SC-PTM cells whose cell quality is above a given threshold. That is, the UE may perform the ranking based cell reselection procedure targeting only SC-PTM cells having good signal strength. In this case, the SC-PTM cell whose cell quality is greater than or equal to the threshold may be a suitable cell.
  • Option 3 If the UE is interested in receiving MBMS, the UE may perform ranking based cell reselection only for the appropriate SC-PTM cell. That is, the UE may determine an appropriate SC-PTM cell according to a suitability check and perform ranking based cell reselection only for the corresponding SC-PTM cell.
  • FIG. 5 illustrates a method of performing cell reselection according to an embodiment of the present invention.
  • the three options described above are applied to each other.
  • step S100 the UE receives from the serving cell an SIB20 including a neighbor cell list providing MBMS via SC-PTM transmission. That is, the UE can identify the neighbor cell providing the MBMS of interest through the SC-PTM transmission by receiving the SIB20 from the serving cell.
  • step S110 the UE determines whether to consider at least one SC-PTM cell included in the neighbor cell list as a target of ranking based cell reselection.
  • step S120 the UE determines the ranking of the SC-PTM cell considered as the target of the ranking based cell reselection. That is, the UE may determine whether to consider the SC-PTM cell as a target of ranking based cell reselection before performing ranking based cell reselection. The UE may determine whether to consider the SC-PTM cell as a target of ranking based cell reselection according to any one of the three options described above, and determine the ranking of the SC-PTM cell determined as the target of ranking based cell reselection. have.
  • Option 1 If the UE is interested in receiving an MBMS, the UE may determine the ranking of the SC-PTM cell by adding an offset to the SC-PTM cell in the neighbor cell list indicated in SIB20. Accordingly, the ranking of the SC-PTM cell may be increased, and the reselection probability of the SC-PTM cell may be increased.
  • Option 2 If the UE is interested in receiving MBMS, the UE is subject to ranking-based cell reselection only for SC-PTM cells whose signal strength is above a given threshold among SC-PTM cells in the neighbor cell list indicated by SIB20. Considering this, the ranking may be determined for only the corresponding SC-PTM cell.
  • Option 3 If the UE is interested in receiving an MBMS, the UE should only target the appropriate SC-PTM cells determined according to the adequacy check among the SC-PTM cells in the neighbor cell list indicated by SIB20 as the target of ranking based cell reselection. In consideration, the ranking may be determined only for the corresponding SC-PTM cell.
  • step S130 the UE performs ranking based cell reselection according to the determined SC-PTM cell ranking.
  • FIG. 6 illustrates a method of performing cell reselection according to another embodiment of the present invention.
  • option 1 is applied to the above three options.
  • the UE determines that it is interested in receiving MBMS.
  • the UE may be either an NB-IoT UE or a UE in enhanced coverage.
  • the UE may be a UE capable of receiving the MBMS via SC-PTM.
  • the MBMS can only be received while the UE camps on the frequency at which the MBMS is provided.
  • step S210 the UE determines the ranking of the SC-PTM cell by adding the SC-PTM offset to a value based on the measurement result of the SC-PTM cell.
  • the SC-PTM offset may be applied to all cells on all frequencies providing the MBMS.
  • the UE may receive from the serving cell an SIB20 including the list of the SC-PTM cells.
  • step S220 the UE performs ranking based cell reselection according to the determined SC-PTM cell ranking.
  • the cell reselection criteria within the conventional frequencies and between frequencies having the same priority may be modified as follows.
  • the cell ranking criterion R s for the serving cell and the cell ranking criterion R n for the neighboring cell are defined by equation (2).
  • Rn Q measn, n -Qoffset-Qoffset temp + Qoffset SCPTM
  • Q meas, s is the RSRP measurement of the serving cell used in cell reselection.
  • Q meas, n is the RSRP measurement of neighbor cells used in cell reselection.
  • Q Hyst is a hysteresis value for the ranking criteria. For intra-frequency, if Qoffset is Qoffset s, n is valid, the Qoffset s, n. Otherwise, Qoffset is zero. Except for NB-IoT and inter-frequency for, Qoffset is the Qoffset s, n is valid, if Qoffset s, n + Qoffset frequency. Otherwise, Qoffset is the Qoffset frequency .
  • Qoffset is effective when the frequency is QoffsetDedicated QoffsetDedicated frequency for all frequencies except the frequency of the only frequency offset. Otherwise, Qoffset is Qoffset freuqency .
  • Qoffset s, n is the offset between two cells.
  • Qoffset frequency is a frequency specific offset for E-UTRAN frequencies of the same priority.
  • Qoffset temp is an additional offset that can be used for cell reselection and is temporarily applied when the RRC connection establishment fails on the cell.
  • Qoffset SCPTM may be the SC-PTM offset described in the embodiment of FIG. 6.
  • Qoffset SCPTM may be an offset used for cell reselection for receiving SC-PTM service for a reduced bandwidth low complexity UE (BL UE), UEs in enhanced coverage, and NB-IoT UEs. have.
  • the same SC-PTM offset may be applied for all frequencies that provide MBMS service over SC-PTM. If Qoffset SCPTM is valid, no Qoffset for neighboring cells between frequencies is used.
  • NB-IoT UEs or UEs in enhanced coverage are capable of receiving SC-PTM, are interested in or are receiving MBMS services, and the UE camps on the frequency (SC-PTM frequency) at which MBMS services are provided. If the MBMS service can only be received during on, the UE may consider the Qoffset SCPTM valid for the MBMS session as long as the following conditions are met:
  • the SIB15 (or SIB15-NB) of the serving cell indicates one or more MBMS SAIs included in the MBMS USD for that frequency; or
  • SIB15 (or SIB15-NB) is not broadcast in the serving cell and its frequency is included in USD for this MBMS service
  • the UE After discontinuing use of Qoffset SCPTM, the UE shall search for high ranking cells on other frequencies for cell reselection as soon as possible.
  • the UE determines the ranking of all cells that meet the cell selection criteria S. However, all CSG cells which are known to the UE not as CSG member cells may be excluded. The cell derives Q meas, n and Q meas, s and calculates the R value using the average RSRP result, so that the ranking is determined according to the above R criteria. If the ranking of the cell is ranked as the best cell, the UE performs cell reselection to that cell. In all cases, the UE reselects the new cell only if the following conditions are met:
  • the new cell is ranked higher than the serving cell during the time interval Treselection RAT ;
  • At least 1 second has elapsed since the UE camped on the current serving cell
  • the UE When the UE using the infinity dB (infinity) on the Qoffset SCPTM, UE has the Qoffset value for the SCPTM to zero, only the cells on the rankings of the first priced SCPTM frequency. If the UE cannot find a suitable cell at the SC-PTM frequency, the UE ranks the cells on all frequencies.
  • FIG. 7 illustrates a wireless communication system in which an embodiment of the present invention is implemented.
  • the eNB 800 includes a processor 810, a memory 820, and a transceiver 830.
  • Processor 810 may be configured to implement the functions, processes, and / or methods described herein. Layers of the air interface protocol may be implemented by the processor 810.
  • the memory 820 is connected to the processor 810 and stores various information for driving the processor 810.
  • the transceiver 830 is connected to the processor 810 to transmit and / or receive a radio signal.
  • the UE 900 includes a processor 910, a memory 920, and a transceiver 930.
  • Processor 910 may be configured to implement the functions, processes, and / or methods described herein. Layers of the air interface protocol may be implemented by the processor 910.
  • the memory 920 is connected to the processor 910 and stores various information for driving the processor 910.
  • the transceiver 930 is connected to the processor 910 to transmit and / or receive a radio signal.
  • Processors 810 and 910 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices.
  • the memories 820 and 920 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media and / or other storage devices.
  • the transceivers 830 and 930 may include a baseband circuit for processing radio frequency signals.
  • the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function.
  • the module may be stored in the memory 820, 920 and executed by the processor 810, 910.
  • the memories 820 and 920 may be inside or outside the processors 810 and 910, and may be connected to the processors 810 and 910 by various well-known means.

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Abstract

La présente invention concerne un procédé et un appareil pour resélectionner une cellule dans un système de communication sans fil. Si un terminal à bande étroite Internet des objets (NB-IoT) ou un terminal ayant une couverture améliorée est intéressé par la réception de services de diffusion/multidiffusion multimédia (MBMS), alors le classement pour une cellule point à multipoint à cellule unique (SC-PTM) est déterminé en ajoutant un décalage SC-PTM à la valeur obtenue sur la base des résultats de la mesure de la cellule SC-PTM qui fournit le MBMS et, conformément au classement déterminé de la cellule SC-PTM, une cellule est resélectionnée sur la base du classement.
PCT/KR2017/010573 2016-10-07 2017-09-26 Procédé et appareil pour supporter une multidiffusion de nb-iot dans un système de communication sans fil WO2018066858A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190261139A1 (en) * 2016-11-04 2019-08-22 Kyocera Corporation Radio terminal and base station
WO2020063617A1 (fr) * 2018-09-26 2020-04-02 JRD Communication (Shenzhen) Ltd. Sélection inter-rat
EP3641405A1 (fr) * 2018-10-19 2020-04-22 Fujitsu Limited Procédé dans un équipement utilisateur, ue, de sélection de cellule, ue et système de communication

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050090278A1 (en) * 2003-08-22 2005-04-28 Samsung Electronics Co., Ltd. Cell reselection method for receiving packet data in a mobile communication system supporting MBMS
WO2016123547A1 (fr) * 2015-01-30 2016-08-04 Kyocera Corporation Sélection de mécanisme de transmission destiné à des services compatibles point à multipoint (ptm), à l'aide des informations de cellule de desserte
WO2016148475A1 (fr) * 2015-03-17 2016-09-22 엘지전자 주식회사 Procédé et dispositif pour transmettre et recevoir une liste de cellules fournissant un service scptm

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050090278A1 (en) * 2003-08-22 2005-04-28 Samsung Electronics Co., Ltd. Cell reselection method for receiving packet data in a mobile communication system supporting MBMS
WO2016123547A1 (fr) * 2015-01-30 2016-08-04 Kyocera Corporation Sélection de mécanisme de transmission destiné à des services compatibles point à multipoint (ptm), à l'aide des informations de cellule de desserte
WO2016148475A1 (fr) * 2015-03-17 2016-09-22 엘지전자 주식회사 Procédé et dispositif pour transmettre et recevoir une liste de cellules fournissant un service scptm

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"3GPP; TSG RAN ; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) Procedures in Idle Mode (Release 14)", 3GPP TS 36.304 V14.0.0, 3 October 2016 (2016-10-03), XP051161175, Retrieved from the Internet <URL:https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=2432> *
"Cell Selection and Reselection in NR", R2-166664, 3GPP TSG-RA N WG2 #95BIS, 1 October 2016 (2016-10-01), Kaohsiung, Taiwan, XP051162207, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_95bis/Docs> *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190261139A1 (en) * 2016-11-04 2019-08-22 Kyocera Corporation Radio terminal and base station
US10798531B2 (en) * 2016-11-04 2020-10-06 Kyocera Corporation Radio terminal and base station
WO2020063617A1 (fr) * 2018-09-26 2020-04-02 JRD Communication (Shenzhen) Ltd. Sélection inter-rat
EP3641405A1 (fr) * 2018-10-19 2020-04-22 Fujitsu Limited Procédé dans un équipement utilisateur, ue, de sélection de cellule, ue et système de communication

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